Manufacturing method of semiconductor device and semiconductor manufacturing apparatus

ABSTRACT

A manufacturing method of a semiconductor device according to the present invention comprises cleaning a semiconductor substrate. A first chemical liquid for forming a water-repellent protection film and a second chemical liquid coating the first chemical liquid are supplied on a surface of the semiconductor substrate. Alternatively, the semiconductor substrate is immersed in the first chemical liquid coated with the second chemical liquid. The semiconductor substrate is then dried.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityunder 35 U.S.C. § 120 from U.S. application Ser. No. 15/408,554 filedJan. 18, 2017, which is a division of U.S. application Ser. No.13/957,697 filed Aug. 2, 2013 (now U.S. Pat. No. 9,583,331 issued Feb.28, 2017), and claims the benefit of priority under 35 U.S.C. § 119 fromJapanese Patent Application No. 2013-007296 filed Jan. 18, 2013, theentire contents of each of which are incorporated herein by reference.

FIELD

The embodiments of the present invention relate to a manufacturingmethod of a semiconductor device and a semiconductor manufacturingapparatus.

BACKGROUND

Semiconductor device manufacturing processes include various processessuch as a lithographic process, an etching process, and an ionimplantation process. After the end of each process and before shiftingto the next process, a cleaning process and a drying process areperformed so as to remove impurities and residues remaining on thesurface of a semiconductor substrate to clean the surface of thesemiconductor substrate.

In recent years, following the downscaling of elements, the aspect ratioof patterns on a semiconductor substrate has become higher. At a higheraspect ratio, there occurs a problem that capillary causes collapsing ofthe patterns on the semiconductor substrate in the drying process.

To deal with such a problem, there has been proposed a technique formaking surfaces of the patterns on the semiconductor substrate waterrepellent and lowering the capillary that acts between the patterns anda chemical liquid or the DIW (Deionized Water). However, awater-repellent agent used for making the surface of the semiconductorsubstrate water repellent is often deactivated after reacting to thewater. For example, it often occurs in a cleaning device that thewater-repellent agent is deactivated after reacting to the water in achamber. If such deactivation of the water-repellent agent occurs, thewater-repellent agent is unable to make the surface of the semiconductorsubstrate water repellent and to suppress collapsing of the patterns onthe semiconductor substrate resulting from the capillary. Furthermore,if the water-repellent agent is deactivated while spreading throughoutthe surface of the semiconductor substrate, water repellency varies onthe surface of the semiconductor substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a configuration of a surface treatmentapparatus 10 according to a first embodiment;

FIG. 2 shows a structure of the chemical-liquid supply unit 240 in moredetail;

FIGS. 3A and 3B shows states where the chemical-liquid supply unit 240supplies the first and second chemical liquids on the semiconductorsubstrate W;

FIG. 4 shows a contact angle θ of a liquid on patterns 4 on thesemiconductor substrate W;

FIG. 5 is a flowchart showing a surface treatment method according tothe first embodiment;

FIG. 6 shows a surface treatment apparatus 20 and a surface treatmentmethod according to a second embodiment; and

FIGS. 7A and 7B show a configuration of the chemical-liquid bath 500 inthe surface treatment apparatus 20 and the surface treatment methodaccording to the second embodiment.

DETAILED DESCRIPTION

Embodiments will now be explained with reference to the accompanyingdrawings. The present invention is not limited to the embodiments.

A manufacturing method of a semiconductor device according to thepresent invention comprises cleaning a semiconductor substrate. A firstchemical liquid for forming a water-repellent protection film and asecond chemical liquid coating the first chemical liquid are supplied ona surface of the semiconductor substrate. Alternatively, thesemiconductor substrate is immersed in the first chemical liquid coatedwith the second chemical liquid. The semiconductor substrate is thendried.

First Embodiment

FIG. 1 shows an example of a configuration of a surface treatmentapparatus 10 according to a first embodiment. The surface treatmentapparatus 10 includes a mounting unit 100 that mounts a semiconductorsubstrate (a wafer) W, a liquid supply unit 200 that supplies liquids tothe semiconductor substrate W, and a chamber 300 that hermetically sealsthe mounting unit 100 and the liquid supply unit 200. The surfacetreatment apparatus 10 is a single-wafer surface treatment apparatusthat processes semiconductor substrates W one by one.

The mounting unit 100 includes a rotary shaft 102, a spin base 103, andchuck pins 104. The rotary shaft 102 extends substantially in a verticaldirection and the disk-like spin base 103 is attached on an upper end ofthe rotary shaft 102. A motor (not shown) can rotate the rotary shaft102 and the spin base 103.

The chuck pins 104 are provided on peripheral edges of the spin base103, respectively. The chuck pins 104 fix the semiconductor substrate Won the spin base 103 by putting the semiconductor substrate W betweenthe chuck pins 104. The mounting unit 100 can rotate the semiconductorsubstrate W while keeping the semiconductor substrate W substantiallyhorizontally.

The liquid supply unit 200 discharges a liquid 1 to a surface of thesemiconductor substrate W near a rotation center thereof. By allowingthe mounting unit 100 to rotate the semiconductor substrate W, thedischarged liquid 1 can spread in a radial direction of thesemiconductor substrate W and can be applied on the surface of thesemiconductor substrate W. Furthermore, by allowing the mounting unit100 to rotate the semiconductor substrate W, the liquid 1 on thesemiconductor substrate W can be drained off and the semiconductorsubstrate W can be spin-dried. The excessive liquid 1 spattering in theradial direction of the semiconductor substrate W is discharged via awaste liquid pipe 105. For example, the liquid 1 is a cleaning liquid, awater-repellent agent, DIW (deionized water) or an organic solvent.

The liquid supply unit 200 includes a cleaning-liquid supply unit 210that supplies the cleaning liquid for cleaning the semiconductorsubstrate W to the surface of the semiconductor substrate W, a DIWsupply unit 220 that supplies the DIW to the surface of thesemiconductor substrate W, an IPA (isopropyl alcohol) supply unit 230that supplies IPA to the surface of the semiconductor substrate W, and achemical-liquid supply unit 240 that supplies a first chemical liquidfor forming a water-repellent protection film and a second chemicalliquid coating the first chemical liquid on the surface of thesemiconductor substrate W.

The cleaning liquid supplied from the cleaning-liquid supply unit 210passes through a supply pipe 212 and is discharged from a nozzle 211.For example, the cleaning liquid is an SC1 liquid (Ammonia-HydrogenPeroxide mixture) or an SPM liquid (Sulfuric acid-Hydrogen PeroxideMixture) and is a chemical liquid used for removing etching residues andthe like.

The DIW supplied from the DIW supply unit 220 passes through a supplypipe 222 and is discharged from a nozzle 221. The DIW is used to rinseaway a chemical liquid on the semiconductor substrate W.

The IPA supplied from the IPA supply unit 230 passes through a supplypipe 232 and is discharged from a nozzle 231. By supplying the IPA, theIPA displaces the liquid 1 on the semiconductor substrate W.

The first and second chemical liquids supplied from the chemical-liquidsupply unit 240 pass through supply pipes 242 and 243, respectively, andare discharged from a nozzle 241. For example, the first chemical liquidis a water-repellent agent for forming a water-repellent protection filmon surfaces of patterns formed on the semiconductor substrate W andmaking the surfaces of the semiconductor substrate W and the patternswater repellent.

The second chemical liquid is a chemical liquid that is lower inspecific gravity than the first chemical liquid so as to coat the firstchemical liquid with the second chemical liquid on the surfaces of thesemiconductor substrate W and the patterns and that is not mixed withthe first chemical liquid. The second chemical liquid is a chemicalliquid that does not react to the first chemical liquid. For example,the first chemical liquid is a water-soluble water-repellent agent andthe second chemical liquid is a water-insoluble chemical liquid. Becausethe second chemical liquid is the water-insoluble chemical liquid, thewater in the chamber 300 is not dissolved in the second chemical liquid.Therefore, it is difficult for the water in the chamber 300 to reach thefirst chemical liquid. Because the first chemical liquid is soluble inwater, the first chemical liquid is not mixed with the second chemicalliquid.

Alternatively, the first chemical liquid can be a water-insolublewater-repellent agent and the second chemical liquid can be awater-soluble chemical liquid. In this alternative, while the secondchemical liquid absorbs the water, the second chemical liquid coats thefirst chemical liquid and is not mixed with the first chemical liquid.Therefore, even in this case, the second chemical liquid can act to keepa water-repellent function of the first chemical liquid.

The second chemical liquid coats the first chemical liquid when thefirst and second chemical liquids are supplied on the semiconductorsubstrate W because the specific gravity of the second chemical liquidis lower than that of the first chemical liquid. That is, the secondchemical liquid stands between the first chemical liquid and anatmosphere in the chamber 300. The second chemical liquid can therebysuppress the contact between the first chemical liquid and the water inthe atmosphere in the chamber 300, and suppress the first chemicalliquid from being deactivated. Because the second chemical liquid is notmixed with the first chemical liquid and does not react to the firstchemical liquid, the second chemical liquid itself does not cause theloss of the water-repellent function of the first chemical liquid.

More specifically, the water-repellent agent serving as the firstchemical liquid is a silane coupling agent. The silane coupling agentcontains hydrolytic groups having an affinity and a reactivity toinorganic materials and organic functional groups chemically bondingorganic materials in molecules. Examples of the silane coupling agentinclude Trichloro-3-chloropropyl silane, 3-Chloropropyltrimethoxysilane,and 3-(Methyldimethoxysilyl)propyl Chloride. These specific examples ofthe silane coupling agent are insoluble in water. Examples of the secondchemical liquid include 3-(Dimethylamino)propylamine, 3-AminopropylMethyl Ether, and Bis(2-ethoxyethyl) Ether. These specific examples ofthe second chemical liquid are soluble in water. To make the surfaces ofthe semiconductor substrate W and the patterns water repellent isdescribed later with reference to FIG. 4.

The surface treatment apparatus 10 can include a vacuum device (notshown) that evacuates the air from an interior of the chamber 300. Inthis case, the vacuum device discharges the water in the chamber 300 tooutside to some extent and the second chemical liquid suppresses thecontact between the first chemical liquid and the water remaining in thechamber 300. It is thereby possible to keep the water-repellent functionof the first chemical liquid for a longer time.

Furthermore, the surface treatment apparatus 10 can include an excimerUV (ultraviolet) irradiation unit (not shown). The excimer UVirradiation unit can selectively remove the water-repellent protectionfilm by irradiating UV light on the semiconductor substrate W.

FIG. 2 shows a structure of the chemical-liquid supply unit 240 in moredetail. The nozzle 241 of the chemical-liquid supply unit 240 has adouble piping structure including a first pipe 245 that supplies thefirst chemical liquid and a second pipe 246 that supplies the secondchemical liquid. The first pipe 245 connects to the supply pipe 242 andtransports the first chemical liquid. The second pipe 246 connects tothe supply pipe 243 and transports the second chemical liquid. Thesecond pipe 246 is provided to surround an outer circumference of thefirst pipe 245. In the first embodiment, the first pipe 245 and thesecond pipe 246 are formed concentrically in cross-sections in aperpendicular direction to a direction in which the first and secondchemical liquids flow. Needless to mention, cross-sectional shapes ofthe first pipe 245 and the second pipe 246 are not limited to circles.However, it is preferable that the first pipe 245 and the second pipe246 are similar in shape in the cross-sections in the perpendiculardirection because the second pipe 246 surrounds the outer circumferenceof the first pipe 245. By allowing the second pipe 246 to surround theouter circumference of the first pipe 245 as described above, the firstand second chemical liquids are supplied on the semiconductor substrateW in a state where the second chemical liquid surrounds the firstchemical liquid. The first chemical liquid can be thereby coated withthe second chemical liquid soon after the first chemical liquid issupplied from the first pipe 245.

FIGS. 3A and 3B shows states where the chemical-liquid supply unit 240supplies the first and second chemical liquids on the semiconductorsubstrate W. In FIGS. 3A and 3B, reference character S1 denotes thefirst chemical liquid and reference character S2 denotes the secondchemical liquid for the sake of convenience. The chemical-liquid supplyunit 240 can supply the second chemical liquid S2 on the surface of thesemiconductor substrate W after supplying the first chemical liquid S1on the surface thereof. First, as shown in FIG. 3A, the chemical-liquidsupply unit 240 supplies the first chemical liquid S1 to the surface ofthe semiconductor substrate W via the first pipe 245. Thereafter, asshown in FIG. 3B, the chemical-liquid supply unit 240 supplies thesecond chemical liquid S2 to the surface of the semiconductor substrateW via the second pipe 246. At this time, the second chemical liquid S2is supplied in a state of surrounding the first chemical liquid S1.Furthermore, the second chemical liquid S2 spreads on the surface of thesemiconductor substrate W in a state of coating the first chemicalliquid S1 because the second chemical liquid S2 is lower in specificgravity than the first chemical liquid S1. This can reduce the timerequired for the first chemical liquid S1 to contact the atmosphere inthe chamber 300. Therefore, the first chemical liquid S1 can spread onthe surface of the semiconductor substrate W without being deactivatedby a reaction to the water in the chamber 300.

Alternatively, the chemical-liquid supply unit 240 can simultaneouslysupply the first chemical liquid S1 and the second chemical liquid S2 onthe surface of the semiconductor substrate W. In this alternative, thechemical-liquid supply unit 240 supplies the second chemical liquid S2in a state of surrounding the first chemical liquid S1 from thebeginning of the supply of the first chemical liquid S1 to thesemiconductor substrate W. The first chemical liquid S1 can therebyspread on the surface of the semiconductor substrate W without beingdeactivated by the reaction to the water in the chamber 300.

FIG. 4 shows a contact angle θ of a liquid on patterns 4 on thesemiconductor substrate W. When an aspect ratio of the patterns 4becomes higher by downscaling the patterns 4, a liquid 5 enters betweenadjacent patterns 4 by the capillary of the liquid 5. In this case,power P with which the liquid 5 acts on the patterns 4 is represented bythe following Equation (1).P=2×γ×cos θ·H/SPACE  (1)

In this equation, SPACE denotes a space between adjacent patterns 4. Hdenotes the height of each pattern 4. γ denotes the surface tension ofthe liquid 5.

It is understood that as the contact angle θ is closer to 90°, then cosθ becomes closer to zero and the power P acting on the patterns 4becomes lower. The fact that the contact angle θ is closer to 90° meansthat the surface of the semiconductor substrate W (the surface of eachpattern 4) is made water repellent. Therefore, pattern collapsing can besuppressed by making the surface of the semiconductor substrate W waterrepellent.

To make the surface of the semiconductor substrate W water repellent,the water-repellent protection film is formed on the surface of thesemiconductor substrate W using the water-repellent agent such as thesilane coupling agent. However, when the water is present in the chamber300, the silane coupling agent has a hydrolytic reaction to the water inthe chamber 300 and loses a water-repellent function. That is, thesilane coupling agent is deactivated. For example, when the silanecoupling agent is supplied to the rotation center of the semiconductorsubstrate W shown in FIG. 1, it is likely that the silane coupling agentreacts to the water and is deactivated before the silane coupling agentspreads through peripheral edges of the semiconductor substrate W. Inthis case, the water-repellent protection film is formed on the patterns4 near a central portion of the semiconductor substrate W but not on thepatterns 4 near the peripheral edges of the semiconductor substrate W.

On the other hand, according to the first embodiment, thechemical-liquid supply unit 240 supplies the second chemical liquid withwhich the first chemical liquid S1 is coated simultaneously with orright after the supply of the water-repellent agent serving as the firstchemical liquid. The second chemical liquid suppresses the contactbetween the first chemical liquid and the water in the chamber 300. Thefirst chemical liquid can thereby spread throughout the surface of thesemiconductor substrate W without the loss of the water-repellentfunction. As a result, it is possible to ensure making the surface ofthe semiconductor substrate W and the surfaces of the patterns 4 waterrepellent, to make the contact angle θ closer to 90°, and to suppresscollapsing of the patterns 4 on the semiconductor substrate W.

FIG. 5 is a flowchart showing a surface treatment method according tothe first embodiment. A control unit (not shown) can control themounting unit 100 and the liquid supply unit 200 to operate.

First, the semiconductor substrate W is mounted on the mounting unit100. Patterns are formed on the surface of the semiconductor substrateW. For example, line-and-space patterns formed by a RIE (Reactive IonEtching) method can be formed as the patterns. Alternatively, resistpatterns formed by a lithographic technique can be formed as thepatterns.

The semiconductor substrate W is rotated at a predetermined rotationalspeed, and the cleaning-liquid supply unit 210 supplies the cleaningliquid to the surface of the semiconductor substrate W near the rotationcenter thereof. The cleaning liquid receives a centrifugal forcegenerated by the rotation of the semiconductor substrate W and spreadsthroughout the surface of the semiconductor substrate W. Thesemiconductor substrate W is thereby subjected to a cleaning treatment(S10). For example, the cleaning treatment removes etching residuesgenerated as a result of the RIE method. In a case of cleaning theresist patterns, a resist-insoluble chemical liquid is used as thecleaning liquid.

Next, the DIW supply unit 220 supplies the DIW to the surface of thesemiconductor substrate W near the rotation center thereof. The DIWreceives the centrifugal force generated by the rotation of thesemiconductor substrate W and spreads throughout the semiconductorsubstrate W. The cleaning liquid remaining on the surface of thesemiconductor substrate W is thereby rinsed away by the DIW (S20: DIWrinse treatment).

The IPA supply unit 230 then supplies the IPA to the surface of thesemiconductor substrate W near the rotation center thereof. The IPAreceives the centrifugal force generated by the rotation of thesemiconductor substrate W and spreads throughout the surface of thesemiconductor substrate W. The DIW remaining on the surface of thesemiconductor substrate W is thereby rinsed away by the IPA (S30:alcohol rinse treatment).

Next, the chemical-liquid supply unit 240 supplies the first and secondchemical liquids to the surface of the semiconductor substrate W nearthe rotation center thereof. The first and second chemical liquidsreceive the centrifugal force generated by the rotation of thesemiconductor substrate W and spread throughout the surface of thesemiconductor substrate W. At this time, the first and second chemicalliquids can be supplied simultaneously. Alternatively, the secondchemical liquid can be supplied after the supply of the first chemicalliquid. The first chemical liquid is the silane coupling agent and formsthe water-repellent protection film on the surfaces of the semiconductorsubstrate W and the patterns (S40: sililation treatment). For example,the first chemical liquid is Trichloro-3-chloropropyl silane,3-Chloropropyltrimethoxysilane or 3-(Methyldimethoxysilyl)propylChloride. For example, the second chemical liquid is3-(Dimethylamino)propylamine, 3-Aminopropyl Methyl Ether orBis(2-ethoxyethyl) Ether. The second chemical liquid coats the firstchemical liquid and is not mixed with the first chemical liquid.Therefore, the second chemical liquid enables the first chemical liquidto spread throughout the surface of the semiconductor substrate Wwithout deactivating the water-repellent function of the first chemicalliquid.

The water-repellent protection film is formed by occurrence of asililation reaction of the silane coupling agent. Therefore, the liquidtemperature can be raised by performing an annealing treatment, or thereaction can be accelerated by causing the excimer UV irradiation unitto irradiate the UV light on the semiconductor substrate W.

Furthermore, when the patterns on the semiconductor substrate W areformed of a silicon-based film such as a silicon nitride film or apolysilicon film, sufficient water repellency is not often ensuredbecause of an insufficient sililation reaction even after the sililationtreatment using the silane coupling agent. In this case, before StepS40, the surfaces of the silicon-based patterns are changed to siliconoxide-based chemical oxide films using another chemical liquid. When thesililation treatment is subsequently performed, it is possible toimprove water repellency after the sililation treatment.

Many residues are generated after the etching by the RIE method. It isdifficult to form the water-repellent protection film in a state wheremany residues remain. Therefore, it is effective to remove the residuesby the cleaning treatment so as to form the water-repellent protectionfilm. In addition, plasma damages are accumulated on the surfaces of thepatterns by the RIE method and dangling bonds are generated. When areforming treatment is performed using a cleaning liquid having anoxidation effect, the dangling bonds terminate at OH groups. If many OHgroups are present, the sililation reaction probability increases, whichfacilitates forming the water-repellent protection film. This canfurther improve the water repellency. Even when the patterns are formedof the silicon oxide film, identical effects can be obtained. When thecleaning liquid has also a reforming effect (an oxidation effect), it ispossible to simultaneously perform the cleaning treatment and thereforming treatment using the single cleaning liquid.

Next, the IPA supply unit 230 supplies the IPA to the surface of thesemiconductor substrate W near the rotation center thereof. The IPAreceives the centrifugal force generated by the rotation of thesemiconductor substrate W and spreads throughout the surface of thesemiconductor substrate W. The first and second chemical liquidsremaining on the surface of the semiconductor substrate W are therebyrinsed away by the IPA (S50: alcohol rinse treatment).

Next, the DIW supply unit 220 supplies the DIW to the surface of thesemiconductor substrate W near the rotation center thereof. The DIWreceives the centrifugal force generated by the rotation of thesemiconductor substrate W and spreads throughout the semiconductorsubstrate W. The IPA remaining on the surface of the semiconductorsubstrate W is thereby rinsed away by the DIW (S60: DIW rinsetreatment).

A drying treatment is then performed on the semiconductor substrate W.For example, the rotational speed for rotating the semiconductorsubstrate W is accelerated to a predetermined spin-drying rotationalspeed, and the DIW remaining on the surface of the semiconductorsubstrate W is drained off and the semiconductor substrate W is therebydried (S70: spin-drying treatment).

In this manner, the water-repellent protection film is formed on thesurfaces of the patterns of the semiconductor substrate W and thesurfaces of the patterns on the semiconductor substrate W are made waterrepellent.

In the first embodiment, the second chemical liquid suppresses thecontact between the first chemical liquid and the water in theatmosphere in the chamber 300 by coating the first chemical liquid withthe second chemical liquid. It is thereby possible to suppress the firstchemical liquid from being deactivated and to make the patterns on theentire surface of the semiconductor substrate W water repellent. Thatis, the water repellency does not vary on the surfaces of thesemiconductor substrate W and the patterns and the water-repellentprotection film is uniformly formed on the surfaces of the patterns. Asa result, according to the first embodiment, the cleaning treatment andthe drying treatment can be performed on the semiconductor substrate Wwhile suppressing collapsing of the patterns on the semiconductorsubstrate W.

Second Embodiment

FIG. 6 shows a surface treatment apparatus 20 and a surface treatmentmethod according to a second embodiment. The surface treatment apparatus20 according to the second embodiment performs processes in Steps S10 toS60 shown in FIG. 5 all by batch processing. That is, the surfacetreatment apparatus 20 processes a plurality of semiconductor substratesW (semiconductor substrates W corresponding to two lots, for example)simultaneously as one batch. As shown in FIG. 6, the surface treatmentapparatus 20 includes a cleaning bath 502 storing therein the cleaningliquid, DIW baths 504 storing therein the DIW, IPA baths 506 storingtherein the IPA, and a chemical-liquid bath 500 storing therein thefirst and second chemical liquids. At the time of performing the dryingtreatment on the semiconductor substrates W, the semiconductorsubstrates W are immersed in the cleaning bath 502, the DIW bath 504,the IPA bath 506, the chemical-liquid bath 500, the IPA bath 506, andthe DIW bath 504 in this order for every batch. At this time, themounting unit 10 can move among the baths 502, 504, 506, 500, 506, and504 while mounting thereon the semiconductor substrates W so that thesemiconductor substrates W can be continuously immersed in these baths.Thereafter, the semiconductor substrates W are pulled out of the DIWbath 504 and subjected to evaporative drying by supplying the dry air tothe semiconductor substrates W from a gas supply unit (not shown). Thesemiconductor substrates W are thereby completed with the cleaningtreatment and the drying treatment. Alternatively, the semiconductorsubstrates W can be subjected to drying under reduced pressure.

Furthermore, while FIG. 6 shows the two DIW baths 504 and the two IPAbaths 506, the surface treatment apparatus 20 can include one DIW bath504 and one IPA bath 506. That is, the common DIW bath 504 and thecommon IPA bath 506 can be used. The surface treatment apparatus 20 canbe thereby made smaller in size. Needless to mention, the surfacetreatment apparatus 20 can include the two DIW baths 504 and the two IPAbaths 506. With this configuration, by sequentially moving the batch ofthe semiconductor substrates W to the adjacent baths, the cleaningtreatment and the drying treatment can be performed as a series ofoperations (sequential operations). In this case, the surface treatmentapparatus 20 can process many batches continuously and swiftly.

FIGS. 7A and 7B show a configuration of the chemical-liquid bath 500 inthe surface treatment apparatus 20 and the surface treatment methodaccording to the second embodiment. In FIGS. 7A and 7B, referencecharacter S1 denotes the first chemical liquid and reference characterS2 denotes the second chemical liquid for the sake of convenience. Thechemical-liquid bath 500 stores therein the first chemical liquid S1 andthe second chemical liquid S2. The chemical-liquid bath 500 can immerseeach batch of the semiconductor substrates W in the first chemicalliquid S1 while mounting the batch on the mounting unit 10. That is, thechemical-liquid bath 500 can perform a water-repellent treatment on aplurality of semiconductor substrates W (a batch thereof) at a time.

The chemical-liquid bath 500 can also include a heater unit (not shown).The heater unit can accelerate the sililation reaction by heating thechemical liquids S1 and S2.

The first and second chemical liquids S1 and S2 that are same as thosein the first embodiment can be used. Therefore, the second chemicalliquid S2 is lower in specific gravity than the first chemical liquidS1, and the first chemical liquid S1 is coated with the second chemicalliquid S2 in the chemical-liquid bath 500. The first chemical liquid S1is the water-soluble water-repellent agent and the second chemicalliquid S2 is the water-insoluble chemical liquid. Alternatively, thefirst chemical liquid S1 is the water-insoluble water-repellent agentand the second chemical liquid S2 is the water-soluble chemical liquid.Accordingly, the first and second chemical liquids S1 and S2 are notmixed with each other. The second chemical liquid S2 thereby suppressesthe contact between an atmosphere outside of the chemical-liquid bath500 and the first chemical liquid S1 and suppresses a reaction betweenthe first chemical liquid S1 and the outside water. As a result, thefirst chemical liquid S1 can keep the water-repellent function for along time. The second chemical liquid S2 can be supplied on the firstchemical liquid S1 after immersing the batch of the semiconductorsubstrates W in the first chemical liquid S1. The semiconductorsubstrates W can be thereby immersed in the first chemical liquid S1without contacting the second chemical liquid S2.

In this manner, while batch processing is performed in the surfacetreatment apparatus 20 and by the surface treatment method according tothe second embodiment, the second embodiment can achieve effectsidentical to those of the first embodiment.

The surface treatment apparatus and the surface treatment methodaccording to each of these embodiments are applicable to, for example,various patterns on the semiconductor substrates W such as sidewall maskpatterns, hard mask patterns or resist patterns in a sidewall transferprocess used when manufacturing a NAND flash memory.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the methods andsystems described herein may be made without departing from the spiritof the inventions. The accompanying claims and their equivalents areintended to cover such forms or modifications as would fall within thescope and spirit of the inventions.

The invention claimed is:
 1. A surface treatment method of asemiconductor substrate comprising: cleaning a semiconductor substrate;rinsing the surface of the semiconductor substrate with deionized water;displacing the deionized water with alcohol; supplying a first chemicalliquid for forming a water-repellent protection film on a surface of thesemiconductor substrate and a second chemical liquid for coating thefirst chemical liquid coating the surface of the semiconductorsubstrate, the second chemical liquid not being mixed with the firstchemical liquid and not reacting to the first chemical liquid, the firstchemical liquid being below the second chemical liquid, and the secondchemical liquid preventing the first chemical liquid from contactingwith water in an atmosphere around the semiconductor substrate; anddisplacing the first chemical liquid and the second chemical liquid withalcohol; rinsing the alcohol with deionized water; and drying thesemiconductor substrate rinsed with the deionized water, wherein thefirst chemical liquid is an insoluble water-repellent agent and thesecond chemical liquid is a soluble chemical liquid, a specific gravityof the second chemical liquid is lower than a specific gravity of thefirst chemical liquid.
 2. The method of claim 1, wherein the firstchemical liquid is a silane coupling agent.
 3. The method of claim 1,wherein the method is performed by a semiconductor processing apparatuscomprising: a cleaning-liquid supply part supplying a cleaning liquidcleaning a semiconductor substrate to a surface of the semiconductorsubstrate; and a chemical-liquid supply part supplying a first chemicalliquid for forming a water-repellent protection film and a secondchemical liquid coating the first chemical liquid on the surface of thesemiconductor substrate without mixing with the first chemical liquid,wherein the chemical-liquid supply part has a double piping structurecomprising a first pipe supplying the first chemical liquid and a secondpipe supplying the second chemical liquid, wherein the second pipe isprovided to surround an outer circumference of the first pipe.
 4. Themethod of claim 1, wherein the method is performed by a semiconductorprocessing apparatus comprising: a cleaning-liquid supply part supplyinga cleaning liquid cleaning a semiconductor substrate to a surface of thesemiconductor substrate; and a chemical-liquid supply part supplying afirst chemical liquid for forming a water-repellent protection film anda second chemical liquid coating the first chemical liquid on thesurface of the semiconductor substrate, wherein the chemical-liquidsupply part has a double piping structure comprising a first pipesupplying the first chemical liquid and a second pipe supplying thesecond chemical liquid.
 5. The method of claim 1, further comprisingrotating the substrate while supplying a first chemical liquid forforming a water-repellent protection film on a surface of thesemiconductor substrate and a second chemical liquid for coating thefirst chemical liquid.
 6. The method of claim 5, wherein supplying afirst chemical liquid for forming a water-repellent protection film andthe second chemical liquid for coating the first chemical liquid nearthe rotation center of the semiconductor substrate.
 7. The method ofclaim 1, wherein supplying the second chemical liquid for coating thefirst chemical liquid is performed right after the supplying a firstchemical liquid for forming a water-repellent protection film.
 8. Asurface treatment method of a semiconductor substrate comprising:cleaning a semiconductor substrate; rinsing the surface of thesemiconductor substrate with deionized water; displacing the deionizedwater with alcohol; supplying a first chemical liquid for forming awater-repellent protection film on a surface of the semiconductorsubstrate and a second chemical liquid for coating the first chemicalliquid coating the surface of the semiconductor substrate, the secondchemical liquid not being mixed with the first chemical liquid and notreacting to the first chemical liquid, the first chemical liquid beingbelow the second chemical liquid, and the second chemical liquidpreventing the first chemical liquid from contacting with water in anatmosphere around the semiconductor substrate; and displacing the firstchemical liquid and the second chemical liquid with alcohol; rinsing thealcohol with deionized water; and drying the semiconductor substraterinsed with the deionized water, wherein the first chemical liquid is awater-soluble water-repellent agent, and the second chemical liquid is awater-insoluble chemical liquid, a specific gravity of the secondchemical liquid is lower than a specific gravity of the first chemicalliquid.
 9. The method of claim 8, wherein the method is performed by asemiconductor processing apparatus comprising: a cleaning-liquid supplypart supplying a cleaning liquid cleaning a semiconductor substrate to asurface of the semiconductor substrate; and a chemical-liquid supplypart supplying a first chemical liquid for forming a water-repellentprotection film and a second chemical liquid coating the first chemicalliquid on the surface of the semiconductor substrate without mixing withthe first chemical liquid, wherein the chemical-liquid supply part has adouble piping structure comprising a first pipe supplying the firstchemical liquid and a second pipe supplying the second chemical liquid,wherein the second pipe is provided to surround an outer circumferenceof the first pipe.
 10. The method of claim 8, wherein the method isperformed by a semiconductor processing apparatus comprising: acleaning-liquid supply part supplying a cleaning liquid cleaning asemiconductor substrate to a surface of the semiconductor substrate; anda chemical-liquid supply part supplying a first chemical liquid forforming a water-repellent protection film and a second chemical liquidcoating the first chemical liquid on the surface of the semiconductorsubstrate, wherein the chemical-liquid supply part has a double pipingstructure comprising a first pipe supplying the first chemical liquidand a second pipe supplying the second chemical liquid.
 11. The methodof claim 8, further comprising rotating the substrate while supplying afirst chemical liquid for forming a water-repellent protection film on asurface of the semiconductor substrate and a second chemical liquid forcoating the first chemical liquid.
 12. The method of claim 8, whereinsupplying a first chemical liquid for forming a water-repellentprotection film and the second chemical liquid for coating the firstchemical liquid near the rotation center of the semiconductor substrate.13. The method of claim 8, wherein supplying the second chemical liquidfor coating the first chemical liquid is performed right after thesupplying a first chemical liquid for forming a water-repellentprotection film.
 14. A surface treatment method of a semiconductorsubstrate comprising: cleaning a semiconductor substrate; immersing thesemiconductor substrate into deionized water bath and isopropyl alcoholbath; immersing the semiconductor substrate through a second chemicalliquid into a first chemical liquid in a chemical-liquid bath, the firstchemical liquid being coated with the second chemical liquid in thechemical-liquid bath, the second chemical liquid not being mixed withthe first chemical liquid and not reacting to the first chemical liquid,and the first chemical liquid being below the second chemical liquid;immersing the semiconductor substrate into isopropyl alcohol bath anddeionized water bath; and drying the semiconductor substrate, whereinthe first chemical liquid is a soluble water-repellent agent and thesecond chemical liquid is an insoluble chemical liquid, or the firstchemical liquid is an insoluble water-repellent agent and the secondchemical liquid is a soluble chemical liquid, a specific gravity of thesecond chemical liquid is lower than a specific gravity of the firstchemical liquid, and the first chemical liquid is a silane couplingagent.